"In using sulphuric acid I dilute it in a little cold water in a cup by pouring the acid on to the water, as sulphuric acid in uniting with water causes a chemical reaction. Where a large quantity of acid is used this reaction is accompanied by a sudden burst of steam, if the water falls upon the acid. But in a small quantity as this, there is no possible danger of accident if the acid is poured on the water. Sulphuric acid should be closely stoppered and used with care, as it is corrosive, eating holes in cotton or linen fabrics. With ordinary precautions it can be used without the least difficulty.
Salts set the dyes
"Glauber salts are too well known in commerce to need description, and are used to neutralize the acid. The two in combination do not injure woolen fabrics, but merely set the dyes.
Preparation of a dye bath
"In preparing the dye bath allow three gallons of water, and 3/4 oz. of sulphuric acid; stir thoroughly and add 3 oz. Glauber salts to six yards of cloth. Then add the dyestuff in required proportions. Stir thoroughly as each ingredient is added, for the evenness of the dye depends upon the thorough distribution of the mordants and color in the dye bath. Generally it is advised to strain the dye before it is added, but, as an even tone is not the desired result for this special handicraft, I never follow this suggestion.
Coloring depends on temperature
"The proper temperature for introducing the color in the bath is not over 150° F., but if one has not a bath thermometer, the temperature must be very hot, yet far below boiling point. Temperature plays a great part in dyeing, for if the dye bath is too hot when the cloth is introduced, the dye, having a great avidity for wool, will be absorbed unequally by the cloth, the ends and outside folds of the cloth absorbing more color than is desired, and the inner folds will have less. I am not discussing the process of dyeing as it should be done on a large scale with vats and suitable reels, etc., but as it is likely to be done by an amateur, in a small way. When the bath is too hot, the cloth takes the dye unequally and is quite spotted. A little irregularity is necessary for a play of color, but it should be secured in a definite way and only to a certain degree, and not as the result of accident. If the cloth has come out spotty, it may be redipped, having added more dye and mordants to the bath, but it will come out a darker shade. If the bath is anywhere near the boiling point before the cloth is dipped, reduce it by adding a quart or two of cold water."
Process of dyeing yarn or raffia
Clear days are best for dyeing
Before dyeing yarn or raffia, bind the skeins loosely in several places to prevent tangling. "Having prepared the bath, gather the cloth in the right hand at half a dozen places along one selvedge, and drop it in, spreading it at once, using two stout sticks, lifting it up and down continually so as to expose all parts to the dye. The temperature should be increased to the boiling point and continued for three-quarters of an hour. Then lift the cloth up and drain it, then rinse in cold water, wring dry, but do not press with an iron, as the soft wooly texture is very desirable. When a quantity of the same color is desired, the same water can be used again by adding acid and Glauber salts, together with more dyestuff with each fresh dip of cloth. It must be stated, however, that the color will not be so clear with succeeding dips, but that does not matter, as a difference is desired. The process of dyeing is very delicate, and the utmost precision must be observed in following proportions and directions regarding temperature, etc. Dyeing is more successful in clear weather than on rainy days, and soft water is required to get good results. If water contains much lime or earthy salts it is unfit for dyeing, and must be neutralized by acetic acid. In such cases it would be still better to use rain water.